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Question for STARFOX or anyone else about PSONE LCDs

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  • Question for STARFOX or anyone else about PSONE LCDs

    I just had a quick question about H-sync and it's role in this mod. I wired mine wayyy back when target had them on clearance for $30. Today I was looking at it and noticed for some reason that I had included the wire for H-sync...Do I need this connection? I have a G200 PCI capable of C-sync, could this connection interefere with stuff? I've noticed some have gotten a little clearer image than me, so I am trying to attain perfection

    Cliff notes

    1. I added a H-sync wire
    2. I have a G200 with C-sync enabled and working
    3. Could this hurt/help? (Hsync)
    4. Thanks for reading

  • #2
    I found the best quality improvement I got was by applying the 4.7k resistor mod in this thread: http://www.diy-tronic.de/forum/viewtopic.php?t=644

    The one posted by Metallhuhn at 8:18am on Friday May 7th.

    The picture got a whole lot brighter and clearer with this mod.
    Old Systems retired due to new car
    New system at design/prototype stage on BeagleBoard.

    Comment


    • #3
      Originally posted by Rob Withey
      I found the best quality improvement I got was by applying the 4.7k resistor mod in this thread: http://www.diy-tronic.de/forum/viewtopic.php?t=644

      The one posted by Metallhuhn at 8:18am on Friday May 7th.

      The picture got a whole lot brighter and clearer with this mod.
      Thanks! I dunno if I should keep the 3 GNDS tied together or just use a DCC signal wire now...but I will keep experimenting as I have some time before I put it all together

      Comment


      • #4
        If your video card is putting out CSync on the VSync pin, and your HSync pin is still connected, just disconnect it. It might cause some image degredation, but you probably won't noticed it that much.. You're better off to ensure that the shielding on your VGA cable is good.

        What did you want to do with DCC? DCC is a ~5V signal line, it's not a ground.

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        • #5
          Originally posted by starfox
          If your video card is putting out CSync on the VSync pin, and your HSync pin is still connected, just disconnect it. It might cause some image degredation, but you probably won't noticed it that much.. You're better off to ensure that the shielding on your VGA cable is good.

          What did you want to do with DCC? DCC is a ~5V signal line, it's not a ground.

          holllly COW. that H-sync pin caused some crazy degredation! once I disconnected it the image improved a ton! I was confused with what to do with the DCC pin, I see now that it's not what I thought.

          On a side note, when I tried the german 4.7k resistor trick, I lost all red, and the images were practically inverted color-wise??? any insight on this?

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          • #6



            got it upright now

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            • #7
              ahhahhaha that is exactly how I did my PSOne by extending the inverter power cable to have the screen stand up
              2004 Matrix XR A7N8X-VM/400 AMD XP-M 2500+, DS-ATX
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              • #8
                Thought you might be interested in seeing what I'm up to with this.

                I have removed the audio circuitary, the RGB switch, the aux-video sync separator, and the pass thru video amp. I think I have found the main sync separator for the main input, which if bypassed (and removed) would remove the need for the 74LS86 based sync combiner for non composite out cards. Currently I have the sync combiner glued to the other side of the board (PSX mod chip stylee) and powered internally.

                Additionally I have found a simpler way of performing the always on mod and have applied the 4.7k redness/brightness hack.

                A scan of my board atm:
                Attached Files
                Old Systems retired due to new car
                New system at design/prototype stage on BeagleBoard.

                Comment


                • #9
                  Yay cool, post more. A friend's been hassling me to trace the composite sync through to where it splits back into hsync and vsync, but i never really had the patience (or a good enough soldering iron) to desolder SMD stuff

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                  • #10
                    I need help on the brightness/redness mod. It seems everyone that has done it has a diff pcb than me. Here are 2 pics, can someone chop them and tell me where to solder the resistor?
                    TIA



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                    • #11
                      You're looking at it upside down
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                      • #12
                        Originally posted by starfox
                        Yay cool, post more.
                        The sync separation happens inside the AN2526 unfortunately, so there is no apparent way to eliminate the sync combiner (74LS86). I have removed what I previously thought was the sync separator - it was actually a switch/amplifier. The combined sync is now fed directly to the AN2526 (via a 10k resistor).

                        I have managed to get a huge improvement in quality by feeding the RGB directly to the capacitors before the AN2526 with standard 75 ohm termination. The colors are now spot on and very sharp, even at low brightness. The (now removed) amplifiers appeared to be emitter followers, non capacitively coupled at the input, so would remove some range.

                        As you can see from the board below, I have removed a large section of it. The goal is to reduce the overall size of the board to approach the size of the LCD module itself. The sync combiner will eventually be relocated to the position of the (now removed) baseband delay chip chip just above the AN2526, and some board trimmed from the other side too.

                        Sorry for the quality of the picture, I just dropped the board on my scanner (no digital camera).
                        Attached Files
                        Old Systems retired due to new car
                        New system at design/prototype stage on BeagleBoard.

                        Comment


                        • #13
                          Ah bummer, sync splitter in the IC... Thanks for posting your findings.

                          By the way, were you able to find a datasheet on the AN2526? Panasonic Semiconductor lists it as a discontinued part and i couldn't find a link to a datasheet for it on their website.

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                          • #14
                            I found a an2526 datasheet

                            http://www.freescale.com/files/micro...ote/AN2526.pdf

                            but appearently it's not a panasonic chip?

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                            • #15
                              Aw dude, you got me all excited, until I found out that was the application note (AN) number 2526 for the motor driver I had already found. It's nothing to do with the IC.
                              Old Systems retired due to new car
                              New system at design/prototype stage on BeagleBoard.

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